Various forms of washing assemblies have been provided for washing both the exterior and interior surfaces of large trailers and other vehicle bodies. There is little difficulty in providing structure for cleaning the external surfaces of trailer bodies inasmuch as the trailer may be driven into the washing position and a generally U-shaped washing assembly may be traversed back and forth along the trailer in order to wash the external surfaces of the opposite sides and top of the trailer. However, the major difficulty resides in providing a structure for adequately washing the internal surfaces of a trailer. Some washing devices have been provided with horizontally swingable booms having washing heads on the free ends thereof and the booms may be swung into and out of washing position within an associated trailer or other load body. In addition, other forms of washers include elongated booms disposed in horizontal position and rearwardly toward a trailer to be washed is backed so that the free end of the boom may be telescopingly received within the trailer. However, this type of construction requires difficult jockeying of the trailer. Still further other forms of interior trailer body washing devices include mobile frames which are driven into the rear of a trailer to be washed from a support platform registered with the open rear of the trailer. However, these different forms of interior trailer washing apparatus include structural and operational features which give rise to functional and operational problems.
Examples of various forms of washing devices for washing the interiors of various forms of vehicle bodies are disclosed in U.S. Pat. Nos. 3,461,889, 3,534,746, 3,689,318, 3,783,466, 3,795,928, 3,830,430 and 3,897,263.